Follow the Water

RUSHANG R. DAVE1, M.H. KALUBARME2

Follow the Water: Site Suitability Analysis of Water Harvesting Structure on Hilly Terrain Using Remote Sensing and Geographical Information System (GIS)

Water is so essential, such a constant feature of our lives, that we sometimes take for granted its dire scarcity in certain parts of the world. Surface water availability varies spatially and temporally based upon the terrain. The scarcity of water affects the overall development of any area and so access to water is a critical element for any development. The areas of Dharmapur and Kaprada Taluka in the Valsad region of South Gujarat, India receive heavy rainfall during the rainy season, but due to lack of water harvesting structures and unsuitable natural topography and geology of the area, the water flows down to the Maharashtra region of Western India. Therefore, tribal peoples living in the Valsad region suffer from acute water scarcity during the summer season.

Working with Manik H. Kalubarme, Project Director at Bhaskaracharya Institute for Space Applications and Geoinformatics (BISAG) in Gujarat, India, I helped to determine a solution to this problem. This was achieved in two stages: first, determining the natural depressions (potential sites) for rainwater harvesting on impervious soil strata using Remote Sensing and Geographic Information Systems (GIS) and second, laying a pipeline on hilly terrain right from the source to destination, so that tribal villages could utilize the water. The natural depressions on the hilly terrains of Dharampur and Kaprada region were determined using Remote Sensing and GIS. Satellite imaging was used to determine the natural depressions on hilly terrain and determine the best potential sites. Natural depressions were chosen with the help of two methods: an analytical method that generated a Digital Elevation Model (DEM) that used the satellite images and geo-spatial method which used Arc GIS 9.1 software by sink method.

The scarcity of water affects the overall development of any area and so access to water is a critical element for any development.

Finally, site suitability analysis was carried out to determine best potential sites that fulfilled all the predefined criteria. For this, a new method known as “Weightage Analysis” was adopted in addition to conventional methods. In this type of analysis, thematic maps such as land usability, geomorphology, soil taxonomy and others were prepared using remote sensing. These layers along with geology and drainage were integrated using GIS techniques to derive suitable water harvesting sites. Each layer was assigned a weightage depending on its influence on surface water recharge. The best suitable sites were submitted to the government for development.

Rushang Dave is a Brevia guest writer from the School of Technology at the Pandit Deendayal Petroleum University. He can be reached at rushangkumardave@yahoo.in.

Update on July 21st, 2014: The site proposed by Rushang as an ideal location for harvesting water has been approved by the government of Gujarat. Construction of the harvesting structure has begun. Rushang and his mentor, Dr. M.H. Kalubarme, have published a paper discussing their work in the International Journal of Scientific and Engineering Research (IJSER). You may read the paper here.